1. Field of the Invention
The present invention relates to a polymeric homogeneous catalyst containing an unsaturated polymer backbone. The polymeric backbone is generated by a ring opening metathesis polymerization reaction (ROMP).
2. Description of the Background
Polymeric catalysts are considered to be quite promising for the production of chemical compounds on an industrial scale due to their possible reuse, which, of course, is expected to provide a substantial reduction in production cost.
Recently, emphasis has been placed on the production of homogeneous forms of catalysts, in particular, because the omission of phase transitions during such catalysis leads to an increase in predictability of the reaction behavior of such catalysts. One of the principal reasons for evaluating increasingly sophisticated catalysts lies in the generation of products in enhanced yields and shorter time periods, i.e., in a more economical way.
The desirability of a catalytic system is predicated upon whether the synthesis of the polymeric portion of such catalysts is facile. DE 19910691.6 and DE 19647892.8 offer different solutions for this problem. Nevertheless, a need still exists for the production of new and different polymeric backbones for such compounds with superior properties.
Conventional polymericallyxe2x80x94enlarged homogeneous catalysts exhibit more or less randomly distributed catalytically active sites along their polymeric backbone and contain an irregular polymer chain, which can deleteriously affect catalytic behavior.
It is, therefore, an object of the present invention to provide a polymerically-enlarged homogeneous catalyst exhibiting a polymeric backbone which is more rigid than conventional ones, and which is, nevertheless, easy to synthesize.
It is also an object of the present invention to provide a method of making the polymerically-enlarged homogeneous catalyst.
It is, moreover, yet another object of the present invention to provide a method of using the present polymerically-enlarged homogeneous catalyst.
The above objects and others are provided by a homogeneous catalyst obtained by reacting a compound of the formula (I), as shown hereinbelow in the specification, in a non-reactive organic solvent or solvent mixture with a bicyclic olefin of the formula (II), as shown hereinbelow in the specification.
The prevention invention provides catalysts, methods of using the same and a method of making the catalysts, the latter of which entails reacting a compound of the formula (I) 
wherein:
D and Q each independently are Cl, Br, I, or OR;
G and Z each independently are PRxe2x80x23, NRxe2x80x2 or D;
Rxe2x80x2 is (C6-C18)-aryl, (C3-C18)-heteroaryl, (C3-C8)-cycloalkyl, (C1-C8)-alkyl, (C6-C18)-aryl-(C1-C8)-alkyl, (C3-C18)-heteroaryl-(C1-C8)-alkyl, (C7-C19)-aralkyl, or (C4-C19)-heteroaralkyl;
M is Ru or Mo;
R is (C6-C18)-aryl, (C3-C18)-heteroaryl, (C3-C8)-cycloalkyl, (C3-C8)-cycloalkenyl, H, (C1-C8)-alkyl, or (C2-C8)-alkenyl;
in a non-reactive organic solvent or solvent mixture with a bicyclic olefin of the formula (II): 
wherein
X is O, NR1, C(R1)2, S, POR6, or PR6;
R1 and R2 are each independently H, (C1-C8)-alkyl, (C2-C8)-alkenyl, (C2-C8)-alkynyl, (C6-C18)-aryl, (C7-C19)-aralkyl, (C3-C18)-heteroaryl, (C4-C19)-heteroaralkyl, (C3-C8)-cycloalkyl, (C3-C8)-cycloalkenyl, (C6-C18)-aryl, (C1-C8)-alkyl, (C3-C18)-heteroaryl-(C1-C8)-alkyl, (C3-C8)-cycloalkyl-(C1-C8)-alkyl, (C1-C8)-alkyl-(C3-C8)-cycloalkyl, or together form an xe2x95x90O group;
R3 and R4, independently of each other, are OR1, SR1, NR21, OR7, SR7, or NR5R7 provided that at least one residue of R3 and R4 bears a group R7;
R6 is R1, with the proviso that R6 is not H; and
R7 is a catalytically active group;
and optionally with a further olefinic compound (III), which is preferably a cycloolefinic compound.
Polymerically enlarged homogeneous catalysts with a rigid unsaturated polymer backbone can be obtained advantageously in a highly modular way, and thus allow a flexible process optimization by combining independently selected bicyclic framework and catalytically active subunits.
In the formula (I), the dashed lines denote the possibility that groups G and Z can be connected to the central atom via a double bond or normal bond. For NRxe2x80x2 as a ligand, for example, and Mo as a central atom, this is the case. Nevertheless, in the case of PR3xe2x80x2 as a ligand and Ru as a central atom a normal bond exists in between.
Compounds of the formula (I) and (II) can be mixed in any proportion. Compound (III) can optionally be added to this mixture, preferably in a range from 0-100 times by weight of the sum of I and II, most preferably between 0-10 times by weight.
In accordance with the present invention, the catalytically activwe subunits embrace the subunit itself optionally combined with a linker between active site and polymer backbone. Such linking molecules are known to those skilled in the art, and may be introduced into the molecule in question by processes known in the art according to the demands of space and electronic behavior of the reaction, as shown below.
Linkers, which are feasible, are alkylenic, arylenic or silylenic linkers, for example. In DE 19910691.6 further linkers are disclosed, which are noted hereinbelow.
In general, any linker or spacer structure may be used which is able to couple the preactive center to the polymer. For example, structures, such as the following may be used. 
Preferred, however, are spacers such as 1,4xe2x80x2-biphenyl, 1,2-ethylene, 1,3-propylene, PEG-(2-10), xcex1, xcfx89-siloxanylene or 1,4-phenylene as well as xcex1, xcfx89-1,4-bisethylenebenzene. Especially preferred are spacers which can be obtained starting from siloxanes of the formula (II): 
These can be easily linked to the double bonds in the polymers and suitable functional groups of the preactive centers under hydrosilylization conditions (the hydrosilylization reaction is reviewed by Ojima in The Chemistry of Organic Silicon Compounds, 1989, John Wiley and Sons Ltd., 1480-1526).
Any low molecular weight catalyst familiar to the person skilled in the art of organic synthesis is suitable as the active center in the polymer-enlarged catalysts. A review of this subject is presented by Noyori in Asymmetric Catalysis in Organic Synthesis, Wiley-Interscience Publication 1994, Chapter 2, 4, 5, by Ojima in Catalytic Asymmetric Synthesis, Wiley-VCH, 1993, and by Bolm and Beller in Transition Metals for Organic Synthesis, Vol. II, Chap. 1 and 2, VCH, 1998.
Preferred catalysts, however, are those from the group of catalysts for transfer hydrogenation and hydrogenation with elemental hydrogen, as are catalysts for the aldol reaction and Mukaijama aldol reaction, dialkyl addition to carbonyl groups, Jacobsen epoxidation, Sharpless dihydroxylation, the Diels-Alder and hetero Diels-Alder reaction, enantioselective anhydride opening, the reduction of ketones with hydrides and the Heck reaction.
The further olefinic compound (III) may be any organic molecule, which contains at least one double bond and which is known to those skilled in the art to be suitable for reacting in a ring opening metathesis reaction. This olefinic compound serves as a means for copolymerization and dilutes the number of active sites per unit of length within the polymeric backbone. Therefore, this is another manner of adapting the catalysts of the present invention to the most suitable demands of space necessary for the reaction in question.
Preferred compounds are ethylene, propene, butene, pentene, isobutene, isopropene and cyclic olefines like cyclopropene, cyclobutene, cyclopentene, cyclopentadiene, cyclohexene, and cycloheptene, for example. Bicyclic olefinic compounds, such as norbornene or azulene, for example, may also be used.
Preferred are catalysts wherein R is Ph, X is O, R1, R2 form together an xe2x95x90O group, R3 is R4, O(C1-C3)-alkyl, and where R4 is OR7, R7 is a catalytically active group of alcohols, amines, phosphines, or other sulfur or phosphorus-containing groups.
More preferably, the catalysts of the present invention have a residue R7, which is a compound of the catalysts mentioned in DE 19910691.6, as suitable for various chemical reactions.
Most preferred are catalysts, such as, for example, Taddol-ligands (Seebach, Helv. Chim. Acta, 1996, 79, 1710f.), chiral salene-complexes (Salvadori), Tetrahedron Lett., 37, 1996, 3375f.), ligands for Sharpless-dihydroxylation like dihydrochinidines (Bolm, i Angew. Chem., 1997, 773f.), 1,2-diaminealcohols (Wandrey, Tetrahedron: Asymmetry, 1997, 8, 1529f.) or hydrogenation catalysts like 1,2-diphosphane-ligands, for example DIOP, DIPAMP; BPPFA, BPPM, CHIRAPHOS, PROPHOS, NORPHOS, BINAP, CYCPHOS, SKEWPHOS 5 (BDPP), DEGPHOS, DUPHOS und PNNP.
Most preferred are the catalysts described in EP 305180, particularly 2-(hydroxydiphenylmethyl)pyrrolidin-4-yl as the active center.
As already mentioned, the catalysts of the present invention can be produced by procedures well known to those skilled in the art with or without linkers between the active subunit and the backbone.
Advantageously, a compound of the formula (1): 
wherein:
D and B each independently are Cl, Br, I, or OR;
G and Z each independently are PRxe2x80x23, NRxe2x80x2 or D;
Rxe2x80x2 is (C6-C18)-aryl, (C3-C18)-heteroaryl, (C3-C8)-cycloalkyl, (C1-C8)-alkyl, (C6-C18)-aryl-(C1-C8)-alkyl, (C3-C18)-heteroaryl-(C1-C8)-alkyl, (C7-C19)-aralkyl, or (C4-C19)-heteroaralkyl;
M is Ru or Mo;
R is (C6-C18)-aryl, (C3-C18)-heteroaryl, (C3-C8)-cycloalkyl, (C3-C8)-cycloalkenyl, H, (C1-C8)-alkyl, or (C2-C8)-alkenyl;
is reacted in a non-reactive organic solvent or solvent mixture with a bicyclic olefin of the formula (II): 
wherein:
X is O, NR1, C(R1)2, S, POR6, or PR6;
R1 and R2, independently of each other, are H, (C1-C8)-alkyl, (C2-C8)-alkenyl, (C2-C8)-alkynyl, (C6-C18)-aryl, (C7-C19)-aralkyl, (C3-C18)-heteroaryl, (C4-C19)-heteroaralkyl,(C3-C8)-cycloalkyl, (C3-C8)-cycloalkenyl, (C6-C18)-aryl, (C1-C8)-alkyl, (C3-C18)-heteroaryl-(C1-C8)-alkyl, (C3-C8)-cycloalkyl, (C1-C8)-alkyl, or (C1-C8)-alkyl-(C3-C8)-cycloalkyl, or form together an xe2x95x90O group;
R3 and R4, independently of each other, are OR1, SR1, NR12, OR7, SR7, NR1R7, provided that at least one residue of R3 and R4 bears a group R7;
R6 is R1, provided that R6 is not H; and
R7is a catalytically active group, and optionally with a further olefinic compound (III), preferably a cycloolefinic compound. wherein:
Preferably a process is chosen, in which compounds (I) and (II) are used wherein R is Ph, X is O, R1, R2 form together an xe2x95x90O group, R3 is R4, O(C1-C8)-alkyl, and R4 is OR7, where R7 is a catalytically active group.
Most preferred is a process, where R7 is a compound selected from above preferred active groups.
A feasible non-reactive organic solvent or at least part of the solvent mixture is a haloalkane, such as, for example, dichloromethane. The process is preferably conducted at temperatures between about xe2x88x9220xc2x0 C. to 50xc2x0 C., more preferably between about xe2x88x925xc2x0 C. and 30xc2x0 C. and most preferably between 5xc2x0 C. and 25xc2x0 C.
The catalysts according to the present invention can be used for organic synthesis. It is preferred that they are used in a reactor, which is able to retain the polymerically enlarged homogeneous catalysts, while permitting the starting material to be introduced in and the product to be released from the reactor. More preferably these catalysts are used in a membrane reactor. Such reactions and reaction conditions are specified in DE 19910691.6, and are incorporated by reference herein in the entirety. When using optically enriched catalysts according to the present invention, a use in a process for the production of optically active compounds is most preferred.
The following scheme illustrates one manner of synthesizing the catalysts of the present invention. 
The catalyst made are employed in a diethyl zinc addition to benzaldehyde as a probe reaction. The results are shown below in Table 1.
Table 1: Reaction of Benzaldehyde and Diethyl Zinc Catalyzed by Various Pyridinyl Alcohols
It is clear from these experiments that the catalysts of the present invention function as versatile tools in homogeneous catalytic organic reactions.
It is explicitly contemplated that each single structure of the chiral catalysts of the present invention includes all and every possible diastereomer whether in racemic form or optically enriched. Each of such diastereomers explicitly embraces and discloses the possible enantiomers as well.
Also explicitly contemplated are the linear or branched (C1-C8)-alkyl radicals methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, heptyl or octyl, as well as all constitutional isomers. The linear or branched (C2-C8)-alkenyl radicals include all substituents listed above in connection with the (C1-C8)-alkyl radical with the exception of the methyl radical, there being at least one double bond present in those radicals. The scope of (C2-C8)-alkynyl corresponds to that of (C2-C8)-alkenyl, but at least one triple bond must be present in that case. (C3-C8)-cycloalkyl is to be understood as being cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl or cyclooctyl radicals.
(C3-C8)-cycloalkenyl denotes cycloalkylic radicals containing one or more double bonds within the residue. (C6-C18)-aryl denotes arylic species with 6 to 18 carbon atoms, like phenyl, naphthyl, phenanthryl. (C7-C19)-aralkyl are arylic radicals connected via a (C1-C8)-alkyl radical with the molecule of respect, for example benzyl, 1-, 2-phenylethyl, naphthylmethyl. (C3-C18)-heteroaryl are arylic molecules in which at least one C-atom is substituted by a heteroatom such as N, O, P, S. Molecules, which may be mentioned, for example, are pyrolyl, furyl, pyridyl, and imidazolyl. (C4-C19)-heteroaralkyl are heteroarylic species bonded via a (C1-C8)-alkyl radical with the molecule in question, such as furfuryl, pyrolylmethyl, pyridylmethyl, furyl-1-, 2-ethyl or pyrolyl-1-, 2-ethyl.